Abstract: To encode a video signal by means of an interlace scanning method, a mode which generates the minimum number of bits with respect to four modes such as frame/field and inter/intra is selected and the video signal of the selected mode is encoded by adaptive frame/field processing. An encoder includes a direct current differential pulse code modulator for performing a direct current differential pulse code modulation only in the frame intramode and the field intramode among four paths to select a predetermined mode, and another direct current differential pulse code modulator for performing a direct current differential pulse code modulation according to the path of the selected mode by selecting one of the delayed signals after selecting the mode. A decoder has the similar constitution to that of the encoder and properly restores the DC value which is differentially pulse code modulated according to a predetermined mode, thereby decoding the restored signal into an original video signal.